Brake shoe



M. H. TRASK Nov. 26, 1935.

BRAKE SHOE Filed Nov. 20, 1933 3 Sheets-Sheet 1 INVENTOR ATTORNEY Nov. 26, 1935. TRAsK 2,022,328

BRAKE SHOE Filed NOV 20, 1933 3 Sheets-Sheet 2 M I Ill WMZ/x INVENTOR ATTORNEY Nov. 26, 1935. H, TRA K 2,022,328

BRAKE SHOE Filed Nov. 20, 1933 asheets-sheet 3 BY -f Mf ATTORNEY Patented Nov. 26, 1935 UNITED A' S PATENT err-ice BRAKE SHOE L Merrill H. Track, Lansing, Mich, assignmoi. onethird to Gordon H. VanBurger and one-third to Harry J. Aldrich, both of Lansing, Mich. Application November zfl, 1933, Serial No. 698,916

3 Claims- (01. 188- 250) This invention relates to safety braking mechanisms for vehicles, and especially for motor cars, and has for its object the combination of parts of special construction and arrangement as described herein, believed to attain in a superior manner and with particularly effective and durable structure, the objects which may be stated as below set forth.

This invention is thought to aiford more braking area in a given, or limited amount of space.

By this invention it is found that the braking heat is distributed over a number of brake linings and brake band surfaces, thus relieving the drum from heat distortion due to the excessive braking heat at high road speeds or under heavy load braking conditions.

This invention attains a slight sliding action between braking surfaces and brake linings at the exact moment of contact, thus preventing lines or scores in or on the drum braking surfaces due to continued braking contacts between brake linings and braking surfaces of the housings and brake drums.

By the employment of this invention there results more brake pounds per square inch of braking surface, with less pressure or force applied to the brake shoes, pedals, levers, or other sources of applied power, due to the fact that angular or curved braking surfaces have a wedge brakin action.

This invention also enables more brake pounds to be applied to the braking surfaces of the drum with less actual direct pounds pressure on the brake linings, due to the angular braking effect and the division of lines of force as applied to the shoe and transferred to the braking surfaces at opposite angles.

The above and other objects and advantages are considered to follow from the use of this invention constructed and arranged as described in this specification and. illustrated in the accompanying drawings.

Fig. l is a vertical section of a brake housing, drum and shoes formed in accordance with the invention, showing the disposition of all parts as assembled.

Fig. 2 is a cross section of the upper part of the assembly in Fig. 1, showing the angular braking surfaces.

Fig. 3 is an enlarged partly sectional view, showing the pivoted ends of the brake shoes in combination with the adjustable cams borne by the shoes, and the adjustable cam plate with the eccentric slots occupied by the pivot pins of the shoes, and the securing means for the various members. I

Fig. 4 shows somewhatenlarged the cam plate which has the eccentric slots, and also the, adjustable cams borne by the pivot pins of the 5 shoes. This view is taken along the broken line 4-,4 of Fig. 3.

Fig. 5 is a cross section of the upper portion of a slightly modified form of this invention with the angular brake linings. I 10 Fig. 6 represents across section of the upper portion of a brake drum and brake, showing a modified form of brake surfaces contemplated by this invention.

Fig. '7 shows a brake drum partly in section and 16 of further modified construction of the drum and brake rotor in'the drum provided with brake band material and angular surfaces.

Fig. 8 is a sectional view of the parts shown in Fig. '7, taken on the broken linev 8-8 of Fig. 7.

Fig. 9 is a perspective view of one of the brakewheel cross ribs used in the-modification illustrated in Fig. 7.

Fig. 10 is-a view from the exterior of the brake drum, showing a portion only thereof. 25

Fig. 11 is a sectional view taken lengthwise of one of the brake shoes as shown in Fig. '7.

Fig. 12 illustrates the connection as made between the brake shoe cross rib and the shoe in accordance with the modification illustrated in 30 Fig. .7.

Throughout the drawings and description the same number is used to refer to the same part.

Considering Figs. 1, 2, 3 and 4, in a housing 4 of any chosen form is located a brake drum 2 35 which may be attached to the wheel not shown of a motor car. A plurality of lining strips 3. of angular cross section are provided within the drum, and air holes 4 are made through the drum to permit air to enter and escape. Rec- 40 tangular brake band strips 5 are secured upon the brake shoes 6 by rivets I, and the brake shoe has a mid rib 8 internally. There is a second and identical brakeshoe 6, and both shoes have pivoted end portions formed with extensions 9 carrying adjustable cams ID on pivot pins II. The cams II] are adjustable upon the pins II and secured to the ends 9 of the shoes by the engagement of the holes 9' in the shoes and the cam securing pins ID, as best illustrated in Fig. 4.

In Fig. 1 will be noted the aligned slots l2 in the housing back plate l3, and the pivot pins ll adjustably engage those slots and are also engaged by the cam plate I4 carried by its center pin l 5 and having two eccentric slots 5 which The free ends of the brakelshoes ai-e forcibly separated to effect the braking actionby' means of the cam I! on cam shaft I 5, best shown in Fig 2, passing through the flange IQ of a conical boss 20, the flange being secured by screws 2| to'the housing back plate l3. The free ends 22 and 23 of the shoes are contiguously located with respect to the cam l1, and whenthe cam is turned the ends are separated and the brake applied.

An opposite movement of the campermits the I spring 24 attached to the shoes to return them into their original postures.- Shoe ends Hand 23 are usually square ends with flat faces. As best shown in Fig. 3, the pivot pins H and II are secured removably in slots l2 by means of nuts 25 on washers 25 engaging the screw termination 21 of the pins, The pin l5 at the center of the cam plate H has a nut 28 on the plate, and a washer 29 upon the rear of the back plate l3 the housing against which is a nut 30, and the washer is secured against turning by a set screw 3| let into the back plate l3. It will be likewise observed in Fig. 3 that the center pin l of the cam plate l4 has the squared portions 32 and 33 in engagement with the cam plates. The

plates cannot, therefore, turn on pin I5 whatsoever force is applied to the brake members. The cam plates are spaced by means of the sleeve 34 on pin I5. 7

Considering Fig. 5, which is a slight modification, the drum 35 has a unique shape, and the rectangular brake lining 35 is held therein by rivets 31. The shoes 38 have the usual mid rib 39 interiorly, with rectangular brake band material 40 held in place by rivets 4|. It will be noted that the drum 35 has flanges 42, for strengthening purposes and to fit certain wheel formations.

Considering Fig. 6, drum 43 has angular lining strips 44, and air holes 45'. The shoe 45 has the mid rib 41, and round strips-of brake band material 48 seated in corresponding grooves in the periphery of the shoe, and held therein by rivets 49.

Considering Fig. '7, the drum 50 is given an angular periphery 5 I, and the shoe rim is angular to fit the interior of the drum and has the bands of brake material 52 riveted thereon. The shoe rim is marked 53, and is best shown in Fig. 12. Supporting the shoe rim are spaced angular ribs There maybe a second 'cam' plate 54, each of which has a slot 55 which engages the mid rib 56 of the shoe. It will be noted in Fig. 11 that the shoe is substantially of the same whole in-place. The ends of the shoe 53 and 58 are 01 the same pattern as the ends 9 and 22 of the shoe shown in the figures first described.

In the operation, the brake is applied by the cam IT as stated, and the angular brake surfaces distribute the braking eflect over a larger area, and result in a greater braking effect by the ear-'15 ertion of a given force. I! the brake materials of the drum lining and brake bands become worn or compressed, the cams carried at the pivoted endsot the shoes are suitably adjusted to take up for the-wear or compression. The operation is the same in the preferred form and in the modified forms.

Having now described this inventionand the manner 01' its use, I claim:--

1. In a brake mechanism, the combination with a brake shoe rim of arcuate form having a middle rib, and a series of transverse ribs or plates in engagement with the said rim and middle rib, the said rim being convex outwardly, and brake bands secured upon opposite sides of said rim externally.

2. In a brake mechanism, the combination with a brake shoe rim of arcuate form provided with a middle rib, the said rib having a series of spaced lugs, thesaid lugs being passed through said rim 85 and headed externally thereupon, the said rim being convex outwardly and concave inwardly as shown, a series of plate ribs arranged in engagement with the said rim and middle rib, and brake bands secured upon opposite sides of the said rim externally.

3. In a brake mechanism, the combination with a brake shoe rim of arcuate form having a middle rib, the said rim being angularly convex outwardly and concave inwardly, the said rib being secured to the rim interiorly along the middle line lengthwise of the rim, a series of plate ribs spaced apart and passing transversely through the said middle rib, each of said transverse ribs being provided with a slot arranged in engagement with the said middle rib, and separate brake bands secured upon opposite sides of said rim externally.

MERRHL H. 'I'RASK. 

